Electric fixture



Oct, 12, 1937. H. A. TEFL-:L

ELECTRIC FIXTURE Filed 0G13. 10, 1934 2 sheets-Shet 1 INVENTOR ATTORNEY.

OCLZ, 1937. H. A, TEPEL 2,095,653

ELECTRIC FIXTURE Filed OCT.. l0, 1954 2 Sheets-Sheet 2 3, if ,33 3.4 ifif \\\m WML; Ummm-m fj' l INVENTOR.

BY //,/l, 7fe/ K /M MM ATTORNEY,

Patented Oct. 12, 1937 FATNT 3 Claims.

This invention relates to electric fixtures and particularly to afastening or connecting means including a keyhole slot with novel meansfor preventing a headed fastener from becoming disengaged from suchkeyhole slot as a result of vibration or other accidental cause.

The principal object of the invention is to provide such fastening meansprovided with projections adjacent the smaller portion of the keyholeslot and adapted to prevent accidental displacement of a headed.fastener received in such small portion to the larger portion of suchkeyhole slot in the event such screw should become loosened as a resultof vibration or other cause. A further object of the invention is toprovide a novel and peculiarly advantageous method of producing a devicehaving the characteristics mentioned. A further object is to provide aplate of a limited size having therein a keyhole slot, provided withsuch means for preventing displacement and associated with means forattaching such plate to a portion of a xture element provided with akeyhole slot whereby the advantageous features of the displacementpreventing means may be realized in connection with fixture elements notoriginally provided with such displacement preventing means. A stillfurther object is to provide for the realization of the invention inconnection with fixture elements composed of materials not readilylending themselves to the incorporation of such displacement preventingmeans as an integral part.

Other and more limited objects will become apparent from the followingdescription when read in connection with the accompanying drawings inwhich Fig. 1 is a fragmentary perspective view illustrating a coverplate embodying one form of the invention; Fig. 2 is a fragmentarydetail plan view of a piece of sheet `metal having formed therein akeyhole slot and provided with the displacement preventing means; Fig. 3is a fragmentary section taken on the line 3 3 of Fig. 2; Fig. 4 is adetail view showing the relation of the keyhole slot and displacementpreventing means to a headed fastener used in connection therewith; Fig.5 is a plan view showing the rst step in the production of one form ofthe invention; Fig. 6 is a fragmentary View showing the second stepwhich is the nicking or partial severance of the central strip fromwhich the displacement preventing projections are formed and showing thenicking die in operative position; Fig. 7 is a plan view showing theresult of the second step; Fig. 8 is a fragmentary sectional viewshowing the manner of bending the projecvably attached thereto by meansof screws.

tions out of the plane of the sheet metal; Figs. 9 and 10 arefragmentary perspective views showing the dies used in the second andthird steps;

Figs. 11 to i6 inclusive are progressive views showing the formation ofa modiiied form embodying means of attachment of a plate of limited sizein which the invention is realized and in which the attaching means arestruck out of the metal from which the device is formed; Fig. 1'7 is asectional view showing a further modified form embodying eyelets ofU-shape or part circular shape instead of the integral means ofattachment; Fig. 18 is a bottom plan `view of the assembly shown in Fig.17; Fig. 19 is a sectional view showing the device of Fig. 17 completedand attached by means of the eyelets to a fixture element and secured inposition by means of a headed fastener; and Fig. 20 is a View similar toFig. 19 showing a guard element in the form of a casting substituted forthe assembly of Fig. 19.

Referring now to the drawings, the numeral Ill indicates a sheet metalelement which may be a portion of a fixture or a plate of limited sizein which is formed a keyhole slot having a larger portion il and anelongated smaller portion I2 adjacent which are projections I3 whichhave been struck up out of the metal of the plate I0. From Figs. 2 and 3it will be obvious that the projections I3 are of a length greater thanhalf the distance across the smaller portion I2 Aof the keyhole slotadjacent which they are formed.

V1t will be noted also that the smaller portion of the keyhole slot hasbeen elongated beyond the length which would have been necessary in theabsence of the projections I3. The length of the smaller portion i2 atthe left of the projections I3 as seen in Fig. 2 must be great enough toaccommodate a headed fastener It in said smaller portion and behind saidprojections I3. The end of the screw It is peened for the purpose ofpreventing complete disengagement thereof from the fixture element I5through which it is threaded and is of a length such that when loosenedas much as the peening will permit will allow the projections I3 to passunder the head of such screw. This provides for removability of theelement lil from the element E5. The length of such screw should not bemuch greater than minimum which will allow such removal.

Fig. 1 shows one application of the invention wherein the numeral I9indicates any sort of fixture element requiring a cover plate I'I'removplate il may have a notch I8 at one side receiv- The Vment to afixture element.

ing a screw I9 and at the other side a keyhole slot extending in asubstantially tangential direction and provided with a larger portionII, a smaller portion I2 and projections I3. Alternatively the plate I'Imay be provided with two or more keyhole slots extending tangentially inthe same circumferential direction whereby rotation of the plate servesto move the same from a position at which the heads of the screws maypass through the largerl ends II of the keyhole slots to the smallerends I2 thereof over the projections I3.

In Figs. 5 to 10 I have disclosed a method of making the keyhole slotsalready described. This method is shown in connection with plates oflimited size adapted for attachment to other xture elements providedwith keyhole slots but it is to beunderstood that the method is the samein its principal features whether it applies to small plates such asthose shown or whether the invention is embodied in fixture portions ofvarious sizes and shapes. The small plates indicated may be cut to thesize shown and the keyhole slot with projections formed therein or thesaid slots may be formed in a strip of metal after whichthey areseparated by means of a severing die or separated in any suitablemanner. The first step in the process consists in punching holes of theshape shown at 2i) and 2I leaving therebetween a strip 22 from which theprojections I3 `are to be formed. The second step comprises nicking thestrip 22 by the action of a V-shaped die 23 while the metal is supportedon a ilat die 24. The result of this operation is seen in plan in Fig.7, the element I@ thereof being shown as a section on the line 6 6 ofFig. 7 would appear. In Fig. 9 I have shown in three dimensions theappearance of the operating portion of the die 23. The next step is theformation of the projections I3 from the metal of the strip I0 by meansof dies 25 and 2B. The die 25 is shown in three dimensions in Fig. 10and comprises a tongue portion 2l' joined with a body portion 28 bymeans of curves 29 of a radius of the order of the thickness of sheetmetal being operated upon. The metal IIB is placed on the die 25 .withthe strip 22 extending across the opening 30 which is of a widthsubstantially equal to the width of the tongue 2l' plus double thethickness of the metal I The tongue 2l is then forced downwardly againstthe resistance of the strip 22, its V-shaped point rst engaging in thenicked portion 3| of the strip 22 and by continued force rupturing theremaining portion of such strip at the point 3l and stretching themetal'of such strip somewhat. Continued downward motion of the die 25results in bending the two portions of the strip 22 out of the plane ofthe metal and to a position outside the boundary of the keyhole slot.The metal adjacent the ends of the strip 22 is drawn and furtherincreases the length of the resulting projectionsV I3 so that the lengthof each of these projections in the finished product is considerablymore than half the distance across the narrower portion I2 of thekeyhole slot.

Figs. 11 to 16 show the formation of a similar plate having integralattaching means for secure- In this case the first step instead ofpunching out holes as indicated at 2B and 2i in the first form describedmerely scores the metal in the outlines shown at 33 and 3s in Fig. lland nicking the strip 35 corresponding to the strip 22 in the precedingform. The scoring may extend part way through as indicated by dottedlines in Fig. 12 or it may extend entirely through the metal. The secondstep shown in Figs. 13 and 14 consists in forming the projections 35 bythe same means as shown in Fig. 8. The third step consists in punchingout the metal within the outline of the scorings 33 and 32 respectivelyto form tongues 36 and 3? for attaching the plate to a fixture elementhaving an opening provided to receive such projections and to leave anopening registering with the main outlines of the keyhole slot 38resulting from the removal of the metal forming the projections 35 andthe tongues 35 and 3l. In Fig. 16 I have indicated in dotted lines afixture .element 39 to which the plate 32 may be attached by turningover the lower ends of the tongues 35 and 3l as indicated in dottedlines at 43 and 4I.

In Figs. 17 to 19 I have shown an embodiment of my invention involvingthe attachment of small plates such as indicated in Figs. 7 and 8 tofixture elements provided originally with keyhole slots of a size toregister with those in the plate by means of eyelets or partial eyelets.In Fig. 17 I have shown a plate It having therein a keyhole slotexhibiting the larger end I I and smaller end i2 together withprojections I3 and secured to a xture element 32 by means of partialeyelets 53 and il@ but not yet bent or crimped over into securingposition. These eyelets as seen in Fig. 18 are of U-shape and providedwith flanges @5 and "it overlying the metal of the plate i It) andfitting snugly into the respective portions of the keyhole slot. Theseeyelets terminate a suiicientrdistance from the projections I3 to permiteasy insertion and to avoid interference with the function of suchprojections. preferably made of quite thin metal, having sufficientextent that no great rigidity is required for performing the securingfunction. These eyelets are also preferably made of soft metal such ascopper or some suitable alloy or thin sheet metal coated with tin orsimilar soft metal having sufficient tensile strength to perform thesecuring function and being sufficiently soft as not to injure porcelainor glass in the event the plate I0 should be secured toI fixtureelements composed of such material. The upper edges of the eyelets i3and 44 as seen in Fig, 17 are bent over into contact with the elementft2, which, as indicated, may be composed of porcelain or other enameledmetal or glass oi' any other material whereby to secure the plate IG tosuch element. The assembly of Fig. 17 with the eyelets bent over isshown in Fig. 19 secured by means of a screw 4l to a xture elementV 48upon which the element 42 which may be for example a reflector issupported. The relation of the length of the screw il? to the projectionI3 should be the same as previously described. An organization such asshown in Fig. 19 lends itself readily to interchangeable use with aguard element consisting of a ring- !ie having a plurality of keyholeslots provided with projections 5U related to the large and smallkeyhole slot openings 5| and 52 in the saine manner as indicated in Fig.2 but formed as a casting and having attached thereto rod or wire guardelements 53 forming a basket-like guard which may enclose a lamp. Itwill be obvious that it may become necessary or desirable to substituteguard assemblies such as indicated for reflector assemblies such asindicated in Fig. 19 and vice versa and that this construction lendsitself readily to such interchangeable use.

While I have shown and described the present preferred embodiments of myinvention I wish lit understood that the same is not limited to the Theeyelets are details shown and described but only in accordance with thescope of the appended claims and the prior art.

Having thus described my invention, what I claim is:

1. In a xture, a sheet metal element having a keyhole slot formedtherein and a pair of opposed projections extending outwardly from theplane thereof and adjacent the edges of the smaller portion of saidkeyhole slot and spaced from the end of said smaller portion a distancesufficient to accommodate the head of a screw in said smaller end ofsaid keyhole slot and contacting the surface of said element, saidprojections being integral with said sheet metal element and of a lengthgreater than half the distance across said smaller end of said keyholeslot, said sheet metal element being of limited extent, in combinationwith another element having a flat portion with a keyhole slot thereinand means securing said sheet metal element to said flat portion withsaid keyhole slots in registration.

2. In a xture, a sheet metal element having a keyhole slot formedtherein and a pair of opposed projections extending outwardly from theplane thereof and adjacent the edges of the smaller portion of saidkeyhole slot and spaced from the end of said smaller portion a distancesuflicient to accommodate the head of a screw in said smaller end ofsaid keyhole slot and contacting the surface of said element, saidprojections being integral with said sheet metal element and of a lengthgreater than half the distance across said smaller end of said keyholeslot, said sheet metal element being of limited extent, in combinationwith another element having a flat portion with a keyhole slot thereinand means securing said sheet metal element to said flat portion withsaid keyhole slots in registration, said means consisting of tonguemeansstruck out ofthe metal of said plate-like element and extending throughthe keyhole slot in said flat portion and bent over the edge thereof.

3. In a fixture, a sheet metal element having a keyhole slot formedtherein and a pair of opposed projections extending outwardly from theplane thereof and adjacent the edges of the smaller portion of saidkeyhole slot and spaced= from the end of said smaller portion a distancesuicient to accommodate the head of a screw in said smaller end of saidkeyhole slot and contacting the surface of said element, saidprojections being integral with said sheet metal element and of a lengthgreater than half the distance across said smaller end of said keyholeslot, said sheet metal element being of limited extent, in combinationwith another element having a flat portion with a keyhole slot thereinand means securing said sheet metal element to said flat portion withsaid keyhole slots in registration, said means including eyelet meansextending through said keyhole slots and bent over the edge thereof.

HERMAN A. TEPEL.

